Lock unit with an extendable latch bolt



Nov. 21, 1967 E. NEARY ET AL.

LOCK UNIT WITH AN EXTENDABLE LATCH BOLT 3 Sheets-Sheet 1 Filed June 18, 1965 [Wm roe! 4 was irroi/vi ff Nov. 21, 1967 R. E. NEARY ET AL 3,353,858

LOCK UNIT WITH AN EXTENDABLE LATCH BOLT Filed June 18,-1965 5 Sheets-Sheet 2 Pa /r i. A sne/ luxni- KuE/Vr/A JcHM/ar Nov. 21, 1967 Filed June 18, 1965 R. E. NEARY ET AL LOCK UNIT WITH AN EXTENDABLE-LATCH BOLT 3 Sheets-Sheet 3 Za /r 6 A/iiP/ (424 raw 6. 77PM:

f/vvewr-aei United States Patent tion Filed June 18, 1965, Ser. No. 465,007 7 Claims. (Cl. 292-464) Our invention relates to means primarily useful as a door lock unit and effective to provide considerably more than the standard excursion of a latch bolt in a door lock unit.

In many installations, the lock unit is provided with an actuator such as a knob or key connected to the latch bolt. Upon a given turn of the actuating knob or a given rotation of the actuating key, the latch bolt is withdrawn from its engagement with the strike. When the actuator is released, a spring returns the latch bolt through its normal excursion and into its home position projecting the maximum distance from the rest of the lock unit. In some commercial lock units, the amount of excursion of the latch bolt is approximately three-eighths or one-half inch. This amount of projection is satisfactory under proper conditions, but there are circumstances wherein it. is insufficient. It is often desired to provide a substantially greater latch bolt projection, say one inch, but this amount of projection may cause difliculty in catching the clothing of a person passing by the open door. Also, this amount of projection of the latch bolt requires substantial changes in the cooperating strike and also may require an extra wide latch bolt in order that the cammin-g action on the latch bolt during door closure will be accomplished at a satisfactory camming angle. While a long latch bolt projection is often desirable it is not always feasible to provide a whole lock set designed for the larger motion but an adaptation to fit the remainder of a standard lock set is a feasible arrangement.

It is therefore an object of the invention to provide a lock unit with an extendable latch bolt having considerably more than the usual excursion or travel, so that more than the usual amount of latch bolt engages with the strike when the door is closed but there is no abnormal projection of the latch bolt when the door is open.

It is also an object of the invention to provide a lock unit with an extendable latch bolt actuated with a standand actuator having only the ordinary amount of excur- SlOIl.

A still further object of the invention is to provide a lock unit with an ex-tendable latch bolt, many parts of which are the same as or are interchangeable with a standard lock unit.

A still further object of the invention is to provide a lock unit with an extend'a-ble latch bolt in which dimensions and shapes of the parts are such as to fit in with a standard lock line not having the extendable latch bolt feature.

A further object of the invention is to provide an improved lock unit with an extendable latch bolt.

Other objects together with the foregoing are attained in the embodiment of the invention described in the accompanying description and illustrated in the accompanying drawings, in which:

FIGURE 1 is a cross section on a horizontal plane Patented Nov. 21, 1967 "ice through a door and door frame showing the lock unit of the invention mounted thereton and in free position, portions of the figure being broken away to reduce its size and some standard parts of the lock unit being omitted;

FIGURE 2 is a cross section similar to FIGURE 1 but taken on a vertical plane, the plane of section being indicated by the line 2-2 of FIGURE 1;

FIGURE 3 is a cross section, the plane of which is indicated by the line 3-3 of FIGURE 2;

FIGURE 4 is a view similar to FIGURE 1 but showing the lock unit in engaged position with the latch bolt extended;

FIGURE 5 is a cross section similar to FIGURE 2 but showing the latch bolt extended;

FIGURE 6 is a view similar to FIGURE 5 but showing a part of the mechanism in la deadlatching condition;

FIGURE 7 is an exploded view of various parts utilized in the lock unit of thepresent invention; and

FIGURE 8 is a diagram showing in plan and in exploded position some of the parts illustrated also in FIG- URE 1, but with transverse portions of these parts greatly exaggerated in length.

The present lock unit can be installed in many different environments, but in a typical case is mounted for use in connection with a door frame 6 having a strike 7 thereon. The strike has an inclined cam portion 8 and is provide-d with an opening 9 through which the latch bolt may pass into a strike box 11 or receptacle within the door fnamei Mounted on the door frame 6 by means of hinges 12 turning about a vertical axis is a door 13 including a panel having a cross bore 14 to receive an actuator unit 16 of a standard sort provided with operating knobs or the like (not shown). The door also has an edge bore 17 merging with the cross bore 14. Situated Within the bore 17 is a circular cylindrical housing 21 symmetrical about a longitudinally extending axis 22 and at its inner end provided with a cross disk 23 having projections 24 adapted to interlock with corresponding portions of the actuating unit 16. At its outer end, the housing 21 has an out-turned flange 26 interfitted with a backing plate 27 and a face plate 28 secured together and inturn secured to the door 13 by any appropriate means, not shown. The face plate 28 has an opening 29 therein. This has a circular portion and has a chordal portion in turn extended by a small, arcuate portion. Thus the face plate has an opening in it overlying part of the housing interior and has a portion of the face plate itself overlying the interior of the housing 21.

Pursuant to the invention, a latch bolt 31 is designed to operate within the housing and in part to pass through the opening 29. The portion 32 of the latch bolt adjacent the interior of the housing is circular cylindrical, so that the latch bolt can slide on the interior of the housing. The latch bolt, however, has a fiat vertical face 33 on one side which lies against the chord'a-l portion of the irregular opening 29. The flat face 33 does not extend for the full length of the latch bolt, but rather terminates, as shown in FIGURE 8, to leave a shoulder 34 which can abut the interior surface of the face plate 28 when the latch bolt is fully extended.

The latch bolt is not entirely solid, but is provided with a longitudinally extending central recess 36 affording a hollow entrance to one end of the latch bolt, the recess itself having an enlargement 37 near its innermost end and having an extension 38 near its outermost end, the enlargement and the extension being demarked by transverse walls 41 and 42. In its interior upper portion the latch bolt is flattened and is formed with a transversely extending, vertical channel 43.

For actuating the latch bolt, there is provided within the housing a lever 51 lying close to the central vertical longitudinal plane of the unit and having at its upper end a first actuating pin 52 extending transversely into the channel 43. When the lever is rocked in one direction, the latch bolt is withdrawn, and when the lever is rocked in the opposite direction, the latch bolt is projected.

The lever 51 is formed with a fulcrum 53 including a pair of aligned oppositely extending pins 54 and 56. The pin 54 extends into and rests on the walls of a slot 57 formed in a longitudinally extending flat and upright retractor bar 58. The other fulcrum pin 56 extends into a journal opening 59 in a spring bracket 61. An arm 62 on the spring bracket passes through an opening 63 in the retractor bar 58 and is bent over on the far side of the opening 63 to alford a foot 64. The spring bracket 61 is approximately S-shape in plan and has an arm 66 terminating in a guide and seat 67. A spring 68 bears against the seat 67 so that the spring bracket is urged toward the face plate end of the housing. When the spring bracket 61 moves relative to the retractor bar 58, the arm 62 can move longitudinally in the elongated opening 63 and the fulcrum pin 54 can move longitudinally in the opening 57.

The retractor bar 58 at its forward end lies with sliding clearance against the upper and lower walls of the recess 36, being partly supported thereby, and in its extreme position is encompassed within the forward reduced extension 38. At its rearward end, the retractor bar passes through an opening 71, the side walls of which serve as a lateral guide, in the cross disk 23 fastened to the inturned ends 73 of the housing 21. The retractor bar is thus supported at widely spaced points for longitudinal transiation. At its inner end, the retractor bar is provided with a T head 74 in part defined by notches 76 and 77 to afi'ord walls interengaging with a slide 78 (FIGURE 2) forming part of the actuator unit 16. When the slide 78 moves in response to key operation or knob rotation and travels to the right in FIGURES 2 and 5, the T head 74 of the retractor bar is engaged and the retractor bar is also translated to the right.

The spring bracket 61 is resiliently positioned since the seat 67 is in engagement with one end of the spring 68 and the other end of the spring 68 rests on a thimble 81 forming part of a bifurcated spring rocker 82. The upper end of the spring rocker bears against and fulcrums on a guide plate 83 spanning the housing 21 and fastened solidly to the housing ends 73. A pair of guides 84 project from the plate 83 and help to position the spring rocker 82. The other ends of the spring rocker 82 bear against the forked arms 85 of a stop bell crank 86 having a fulcrum portion 87 adapted to abut the guide plate 83. Under the urgency of the spring 68 at least, the spring rocker 82 tends to turn in a counterclockwise direction and tends to turn the stop bell crank 86 in a clockwise direction.

Clockwise rocking motion of the stop bell crank 86 is limited because an outstanding lip 88 on the bell crank 86 comes into abutment with a surface 89 (FIGURE 7) on the retractor bar 58. Alongside the retractor bar 58 is a plunger bar 91 having an elongated opening 92 therein, the walls of which rest against the central portion of the turned foot 64 of the spring bracket 61. This portion of the plunger bar is thus supported for rectilinear motion. The plunger bar 91 also has an inturned end 93 with a T head 94 thereon disposed on one side of an elongated opening 96 cut through the forward end of the retractor bar and the inturned end 93 riding on the walls of the opening 96. This end of the plunger bar is thus supported for rectilinear translation. Adjacent its central portion the plunger bar 91 has depending lugs 97 and 98 between them defining a notch 99, the walls of which abut a second actuating pin 101 like the pin 52 but on the opposite side of the lever 51 from the fulcrum pins 54 and 56.

The plunger bar 91 is further formed with a pair of fingers 103 and 104- extending laterally to lie between walls 106 and 107 defining a groove 108 in a deadlatch plunger 109. This plunger is mostly circular cylindrical in configuration except for a fiat, chordal face 111 extending for part of its length. The fiat face 111 lies against the flat face 33 of the latch bolt and terminates to leave a shoulder 112 adapted to abut an inner end face 113 of the latch bolt.

The deadlatch plunger has a circular cylindrical extension 114 designed to guide and seat a second coil spring 116 like the spring 68 and resting against a second thimble 117 formed on the rocker 82 on the other side from the thimble 81.

With this portion of the mechanism, when the door is at least partly open, as shown in FIGURES 1 and 2, the effect of the spring 68 acting against the spring bracket 61 is to extend the latch bolt 31 and the effect of the spring 116 is to extend the deadlatch plunger 109. The force of the spring 68 on the spring bracket 61 isv transmitted to the lever 51 and to the plunger bar 91 and finally to the retractor bar 58. The latch bolt 31 is urged into a forward position with about the normal amount of projection from the face plate 28 and the deadlatch plunger 109 likewise projects about the normal amount from the face plate 28. Under these circumstances, the lever 51 occupies the position shown in FIGURE 2.

When the slide 78 is actuated and withdraws the retractor bar 58, the lever 51 does not rotate and the re tractor bar carries the plunger bar 91, the deadlatch plunger 109, the latch bolt 31, the spring bracket 61 and the lever 51 with it, so that these parts are all retracted into the housing 21. In this way, the latch bolt and the deadlatch plunger are simultaneously retracted to provide a normal actuation of the mechanism from normal position.

normal spring-loaded position as shown in FIGURE 2, for example, and when the door is moved from its open position toward closed position, the latch bolt rides over the entry portion, 8 of the strike 7 and depresses the latch bolt by an exterior force. The yielding motion of the latch bolt permits the door to close. The latch bolt rides over the strike 7 and is gradually depressed until such time as the face 33 of the latch bolt clears the margin of the opening 9 in the strike plate. Having passed that point, the latch bolt is immediately spring expelled and lodges in the strike box 11.

At the time the latch bolt is depressed, the deadlatch plunger 109 is carried into the housing 21 by the end face 113 acting against the shoulder 112. The deadlatch plunger, moving inwardly throughout a normal traverse as the door closes, causes a similar inward movement of the plunger bar 91, thus translating the walls of the slot 99 inwardly and carrying the actuating pin 101 on the lever 51 therewith. The deadlatch plunger, however, does not have any accommodation in the opening 9 to enter the strike box 11 and remains depressed in contact with the strike plate 7. When the latch bolt is expelled the lever 51 rocks about the pin 101 then in inner position so that the first actuator pin 52 in engagement with the wall 41 of the channel 43 in the latch bolt advances the latch bolt in an over-travel stroke.

The total excursion of the latch bolt from the housing 21, including the normal stroke and the over-travel stroke, 6

is approximately twice the normal excursion and the latch bolt extends into the strike box approximately twice the normal amount. Thus the extenda-ble latch bolt is etiective to span even an extraordinary depth of strike When the slide 78 is not manually operated and is in its.

box and'toextend far into the door jamb. The latch bolt is engaged so farinto the strike box thatextra security and extra latch bolt coverage are provided. Much more than the customary lateral bearing surfaces are provided so that there is added resistance to lateral forces.

When it is desired to open the door, the ordinary actuating means are rotated, .thus retracting the slide 78 and causing a corresponding withdrawal of the retractor bar 58. Since thepin 101 is held stationary by the plunger bar 91 and the deadlatch plunger 109, this retraction of the bar 58 is effective upon the fulcrum pins 54 and 56 and rocks the lever 51 in a clockwise direction as seen in FIGURE 5, for example, so that there is a full retraction of the extraordinarily extending latch bar. The door can then be opened. Upon release of the knob when the door is open, the slide 78 is returned to its normal position by the llSllZll springs and lock parts revert to their positions as shown in FIGURES 1 and 2, with the latch bolt and deadlatch plunger about flush at their ends, which is then the normal relationship.

The deadlatch plunger 109 is utilized to afford an extraordinary excursion of the latch bolt. Also, the deadlatch plunger has its customary function to provide a deadlatching feature. The spring bracket 61 is contoured to provide a stop lug 121 moving in a rectilinear path. Whenever the lip 88 of the bell crank 86 is rotated by spring force, it lies in the path of the lug 121 and prevents further retraction of the spring bracket 61. During ordinary retraction, the lip 88 is prevented from rising and is depressed out of the path of the stop lug 121 by a cam 122 on the retractor '58. There is always a ready retraction of the latch bolt whenever the slide 78 Withdraws it by an internal force.

If, when the door is closed and the deadlatch plunger 109 is in depressed position against the strike 7, as shown in FIGURE 4, some external force tends to depress or push in the latch bolt, the latch bolt cannot be moved far enough inward to release from the strike box. The deadlatch plunger in its depressed position acts through the fingers 103 and 104 to hold the plunger bar 91 in position. This in turn, acting through the lugs 97 and 98, holds the lever pin 101. A slight depression of the latch bolt 31 moves the pin 52 and rocks the lever 51 about the pin 101 as a pivot. The pin 56 thus slightly depresses the spring bracket 61 until the stop lug 121 butts against the lip 88 and is blocked. There is thus formed a straight bar mechanism transmitting the depressing force against the cross disc 23 and precluding further depression of the latch bolt from outside. The lock unit is therefore deadlatched. This deadlatching feature is not effective when the door is open and the deadlatch plunger is projected. External depression of the latch bolt at that time translates the retractor bar inwardly and the cam lug 122 on the retractor bar slightly precedes the stop lug 121 and cams the lip 88 of the crank 86 out of the way of the stop lug so as no straight bar linkage is formed.

What is claimed is:

1. A lock unit with an extendable latch bolt compris ing a housing, a face plate having an opening therein, means for securing said face plate to said housing with said opening overlying part of the interior of said housing and with part of said face plate overlying part of the interior of said housing, a latch bolt disposed for reciprocation in said housing and through said opening, means on said latch bolt in one position thereof adapted to abut said part of said face plate, means in said latch bolt defining a guide, means in said housing defining a support, a retractor bar supported in said guide and in said support for reciprocation in said housing, a spring bracket, means for mounting said spring bracket on'said retractor bar for limited sliding motion relative thereto, a first spring in said housing and engaging said spring bracket for urging said spring bracket and said retractor bar to ward said face plate, a lever, a fulcrum shaft engaging said lever and journalled in said spring bracket and slid- 6 ably supported in said retractor bar, a first actuating pin on said lever near one end thereof, means on said latcli bolt defining a channel extending transversely with respect to said retractor bar and adapted to receive said first actuating pin, a plunger cam bar in said housing,

means for mounting said plunger cam bar for reciprocation alongside said retractor bar, a deadlatch plunger disposed in said housing for reciprocation therein and through said opening in said face plate, means interen-gaging said plunger cam bar and said plunger for reciprocation together, a second spring in said housing and engaging said plunger for urging said plunger and said plunger cam bar in'the direction of said face plate, a second actuating pin on said lever near the other end thereof, means on said plunger cam bar and adapted to receive said second actuating pin, a stop bell crank fulcrumed in said housing and having a stop arm and having spring arms, means for transferring the force of said first spring and said second spring to said spring arms to urge said stop arm into stop position, a stop lug on said spring bracket adapted to engage said stop arm in said stop position, a cam lug on said retractor bar adapted to engage said bell crank and to earn said stop arm out of said stop position, and means on said plunger cam bar for engaging said bell crank and holding said stop arm out of said stop position.

2. A lock unit with an extendable latch bolt as in claim 1 in which said first actuating pin is about twice as far from said fulcrum shaft as said second actuating pin is.

3. A lock unit with an extendable latch bolt comprising a housing, a face plate having an opening therein, means for securing said face plate to said housing across one end thereof, a latch bolt, means for mounting said latch bolt for reciprocation in said housing and through said opening, a retractor bar, means for mounting said retractor bar for reciprocation in said housing, means for connecting said retractor bar to said latch bolt for reciprocating said latch bolt through a predetermined distance, a deadlatch plunger, means for mounting said deadlatch plunger for reciprocation in said housing and through said opening, and means including a lever having one portion connected to said deadlatch plunger, another portion connected to said latch bolt, and a third portion fulcrumed on means other than said deadlatch plunger and said latch bolt for reciprocating said latch bolt a distance greater than said predetermined distance in response to reciprocation of said deadlatch plunger including a lever connected to and in accordance with said reciprocation of said deadlatch plunger.

4. A lock unit with an extendable latch bolt as in claim 3 in which both said retractor bar and said deadlatch plunger are connected to said latch bolt through said lever.

5. A lock unit with an extendable latch bolt comprising a housing structure having an opening therein, a retractor bar movable between an advanced and a retracted position in said housing structure, a lever, means for connecting the fulcrum of said lever tosaid retractor bar, a latch bolt separate from said retractor bar and adapted to operate through said opening, means for connecting said latch bolt to one arm of said lever, a plunger adapted to operate through said opening between an advanced and a retracted position, means for connecting said plunger to the other arm of said lever, first spring means connected to urge said retractor bar toward said advanced position, and second spring means connected to urge said plunger toward said advanced position.

6. A lock unit with an extendable latch bolt as in claim 5 in which said means for connecting the fulcrum of said lever to said retractor bar is a lost motion connection.

7. A lock unit with an extendable latch bolt comprising a housing, a retractor bar, means for mounting said retractor bar for reciprocation in said housing through a predetermined distance, a lever, means for fulcruming said lever on said retractor bar for pivotal motion, a latch 7 8 bolt, meansv for mounting said latch bolt for reciprocation 2,711,920 6/ 1-955 Farnsworth 292-169 in said housing, means for connecting. one end ofsaid 2,813,740 11/1957 Schlage 292169 'lever to said latch bolt, and means movably mounted in said housing and connected to the otherv end of said lever FOREIGN PATENTS for pivoting said lever and thereby reciprocating said 5 905,373 4/1945 Fr ncelatch bolt, independently of movement of said. retractor 936,018 2/1943 F ancebar, through a distance dilferent than said predetermined 99,038 8/1937 Sweden. distance.

Ref Cit d FRANCIS K. ZUGEL, Primary, Examiner. UNITED STATES PATENTS 10 EDWARD C. ALLEN, MARVIN A. CHAMPION, 1,212,117 1/1917 Schoell 711-1 43 4 1,585,105 5/1926 Overdick 70-143 J. R. MOSES, Assistant Examiner. 

7. A LOCK UNIT WITH AN EXTENDABLE LATCH BOLT COMPRISING A HOUSING, A RETRACTOR BAR, MEANS FOR MOUNTING SAID RETRACTOR BAR FOR RECIPROCATION IN SAID HOUSING THROUGH A PREDETERMINED DISTANCE, A LEVER, MEANS FOR FULCRUMING SAID LEVER ON SAID RETRACTOR BAR FOR PIVOTAL MOTION, A LATCH BOLT, MEANS FOR MOUNTING SAID LATCH BOLT FOR RECIPROCATION IN SAID HOUSING, MEANS FOR CONNECTING ONE END OF SAID LEVER TO SAID LATCH BOLT, AND MEANS MOVABLY MOUNTED IN 